/* -*- mode: c++; indent-tabs-mode: nil -*- */
/*
  ParseReferenceNode.h

  Qore Programming Language

  Copyright (C) 2003 - 2015 David Nichols

  Permission is hereby granted, free of charge, to any person obtaining a
  copy of this software and associated documentation files (the "Software"),
  to deal in the Software without restriction, including without limitation
  the rights to use, copy, modify, merge, publish, distribute, sublicense,
  and/or sell copies of the Software, and to permit persons to whom the
  Software is furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  DEALINGS IN THE SOFTWARE.

  Note that the Qore library is released under a choice of three open-source
  licenses: MIT (as above), LGPL 2+, or GPL 2+; see README-LICENSE for more
  information.
*/

#ifndef _QORE_INTERN_PARSEREFERENCENODE_H
#define _QORE_INTERN_PARSEREFERENCENODE_H

#include <qore/intern/ParseNode.h>

class IntermediateParseReferenceNode;

class ParseReferenceNode : public ParseNode {
protected:
   //! lvalue expression for reference
   AbstractQoreNode* lvexp;

   //! frees all memory and destroys the object
   DLLLOCAL ~ParseReferenceNode() {
      if (lvexp)
         lvexp->deref(0);
   }

   // returns a runtime reference (ReferenceNode)
   DLLLOCAL virtual QoreValue evalValueImpl(bool& needs_deref, ExceptionSink* xsink) const {
      return evalToRef(xsink);
   }

   DLLLOCAL AbstractQoreNode* doPartialEval(AbstractQoreNode* n, QoreObject*& self, const void*& lvalue_id, ExceptionSink* xsink) const;

   //! initializes during parsing
   DLLLOCAL virtual AbstractQoreNode* parseInitImpl(LocalVar* oflag, int pflag, int& lvids, const QoreTypeInfo*& typeInfo);

public:
   //! creates the ReferenceNode object with the given lvalue expression
   /** @param exp must be a parse expression for an lvalue
    */
   DLLLOCAL ParseReferenceNode(AbstractQoreNode* exp) : ParseNode(NT_PARSEREFERENCE, true, false), lvexp(exp) {
   }

   //! concatenate the verbose string representation of the value to an existing QoreString
   /** used for %n and %N printf formatting
       @param str the string representation of the type will be concatenated to this QoreString reference
       @param foff for multi-line formatting offset, -1 = no line breaks (ignored in this version of the function)
       @param xsink ignored in this version of the function
       @return this implementation of the function always returns 0 for no error raised
   */
   DLLLOCAL virtual int getAsString(QoreString& str, int foff, ExceptionSink* xsink) const {
      str.sprintf("parse reference expression (%p)", this);
      return 0;
   }

   //! returns a QoreString giving the verbose string representation of the value
   /** Used for %n and %N printf formatting.  Do not call this function directly; use the QoreNodeAsStringHelper class (defined in QoreStringNode.h) instead
       @param del if this is true when the function returns, then the returned QoreString pointer should be deleted, if false, then it must not be
       @param foff for multi-line formatting offset, -1 = no line breaks (ignored in this version of the function)
       @param xsink ignored in this version of the function
       @see QoreNodeAsStringHelper
   */
   DLLLOCAL virtual QoreString* getAsString(bool &del, int foff, class ExceptionSink* xsink) const {
      del = true;
      QoreString* rv = new QoreString();
      getAsString(*rv, foff, xsink);
      return rv;
   }

   //! returns the type name as a c string
   DLLLOCAL virtual const char* getTypeName() const {
      return "reference to lvalue";
   }

   DLLLOCAL virtual const QoreTypeInfo* getTypeInfo() const {
      return referenceTypeInfo;
   }

   // returns an intermediate reference for use with the backgroun operator
   DLLLOCAL IntermediateParseReferenceNode* evalToIntermediate(ExceptionSink* xsink) const;

   // returns a runtime reference
   DLLLOCAL virtual ReferenceNode* evalToRef(ExceptionSink* xsink) const;
};

class IntermediateParseReferenceNode : public ParseReferenceNode {
protected:
   QoreObject* self;
   const void* lvalue_id;

   DLLLOCAL virtual bool derefImpl(ExceptionSink* xsink) {
      if (lvexp)
         lvexp->deref(xsink);
      lvexp = 0;
      return true;
   }

public:
   DLLLOCAL IntermediateParseReferenceNode(AbstractQoreNode* exp, QoreObject* o, const void* lvid) : ParseReferenceNode(exp), self(o), lvalue_id(lvid) {
   }

   // returns a runtime reference
   DLLLOCAL virtual ReferenceNode* evalToRef(ExceptionSink* xsink) const {
      return new ReferenceNode(lvexp->refSelf(), self, lvalue_id);
   }
};

#endif // _QORE_INTERN_PARSEREFERENCENODE_H
